全文获取类型
收费全文 | 3568717篇 |
免费 | 268455篇 |
国内免费 | 10287篇 |
专业分类
耳鼻咽喉 | 50679篇 |
儿科学 | 115036篇 |
妇产科学 | 100417篇 |
基础医学 | 492956篇 |
口腔科学 | 102976篇 |
临床医学 | 336845篇 |
内科学 | 699675篇 |
皮肤病学 | 85288篇 |
神经病学 | 294954篇 |
特种医学 | 137492篇 |
外国民族医学 | 1180篇 |
外科学 | 538131篇 |
综合类 | 74114篇 |
现状与发展 | 49篇 |
一般理论 | 1398篇 |
预防医学 | 274011篇 |
眼科学 | 82452篇 |
药学 | 258243篇 |
13篇 | |
中国医学 | 7207篇 |
肿瘤学 | 194343篇 |
出版年
2018年 | 42327篇 |
2017年 | 34395篇 |
2016年 | 39007篇 |
2015年 | 43198篇 |
2014年 | 59569篇 |
2013年 | 87387篇 |
2012年 | 106615篇 |
2011年 | 112406篇 |
2010年 | 71304篇 |
2009年 | 69978篇 |
2008年 | 105871篇 |
2007年 | 112343篇 |
2006年 | 114738篇 |
2005年 | 109368篇 |
2004年 | 105330篇 |
2003年 | 101700篇 |
2002年 | 98302篇 |
2001年 | 163193篇 |
2000年 | 166710篇 |
1999年 | 141755篇 |
1998年 | 42589篇 |
1997年 | 37950篇 |
1996年 | 37466篇 |
1995年 | 35986篇 |
1994年 | 32869篇 |
1993年 | 30701篇 |
1992年 | 110243篇 |
1991年 | 106401篇 |
1990年 | 103257篇 |
1989年 | 100190篇 |
1988年 | 92488篇 |
1987年 | 90538篇 |
1986年 | 85592篇 |
1985年 | 81793篇 |
1984年 | 61442篇 |
1983年 | 52284篇 |
1982年 | 31500篇 |
1981年 | 28274篇 |
1979年 | 55710篇 |
1978年 | 39747篇 |
1977年 | 34260篇 |
1976年 | 31397篇 |
1975年 | 34326篇 |
1974年 | 40459篇 |
1973年 | 38824篇 |
1972年 | 36691篇 |
1971年 | 34178篇 |
1970年 | 31926篇 |
1969年 | 30745篇 |
1968年 | 28520篇 |
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
51.
52.
53.
M. Corral-Blanco V.C. Prudencio-Ribera M.E. Jarrín-Estupiñán R. Alonso-Moralejo V. Pérez-González J.C. Meneses-Pardo A. Hermira-Anchuelo A. De Pablo-Gafas 《Transplantation proceedings》2019,51(2):380-382
Background
Pulmonary hypertension (PH) is a comorbidity associated with interstitial lung disease (ILD). The purpose of this study was to evaluate the influence of PH on intrahospital mortality in lung transplantation (LT) for ILD.Methods
We conducted a retrospective cohort study of 66 patients who underwent LT for ILD at the 12 de Octubre University Hospital (Madrid, Spain) from October 2008 to June 2014. PH was defined as mean pulmonary arterial pressure (mPAP) ≥25 mmHg on right-sided heart catheterization and intrahospital mortality as any death taken place after the transplantation of patients not being discharged.Results
We retrospectively analyzed data of 66 patients; they were stratified by the presence or absence of PH before LT. Twenty-seven patients (41%) had PH. The PH group had a lower diffusing capacity of carbon monoxide (DLCO), carbon monoxide transfer coefficient (KCO), and 6-minute walk distance test (6MWT) and a higher total lung capacity (TLC), modified medical research council dyspnea scale (mMRC), and lung allocation score (LAS) than the non-PH group. Patients with PH more often underwent double lung transplantation (DLT; 59%) than single lung transplantation (SLT).Intrahospital mortality was 13% (9/66). No significant differences were observed in Kaplan-Meier survival curves for the PH and non-PH groups with a median survival time of 46 days versus 33 days (IQR 26–74; log-rank P = .056); however, the postoperative length of stay in the hospital was greater in the PH group.Conclusions
In our cohort, pulmonary hypertension was not related to early mortality in lung transplantation recipients for interstitial lung diseases. 相似文献54.
Amgad El Mekabaty Monica S. Pearl Bommy Mershon Ivor Berkowitz Philippe Gailloud Thierry A.G.M. Huisman 《Journal of neuroradiology. Journal de neuroradiologie》2019,46(3):214-221
Background and purpose
The vein of Galen aneurysmal malformation (VGAM) is a rare congenital vascular malformation with a higher morbidity and mortality, especially in neonates. Ultrasound, CT and MR are usually used in diagnosis and treatment monitoring of these disorders. In this current study, we aim to examine utility of SWI in evaluation of treatment response in infants with VGAM.Materials and methods
We performed a retrospective chart analysis of children with VGAM in our institution between January 2008 and December 2016. Inclusion criteria included; confirmed VGAM on DSA; available SWI sequence at baseline and at follow up after at least a single embolization session; age at initial MR of 18?years or younger. Signal intensity and Angioarchitecture of VGAM and cerebral veins on SWI, as well as hydrocephalus and clinical outcome were evaluated.Results
Of 11 patients identified with VGAM in our institution, 5 children (3 males and 2 females) satisfied the inclusion criteria. The average age at initial MR was 29?days (range 1–120). Fourteen MRI were available for review. All children had VGAM of mural type. Intramedullary veins were dilated and SWI-hypointense in all children, while subependymal and sulcal veins were dilated and SWI-hypointense in 4 patients on initial MRI. On the first available follow up MRI, cerebral veins have mostly normalized in 4 children and remained mostly dilated and SWI-hypointense in 1 child; even after complete treatment of the VGAM.Conclusion
Our preliminary findings show that SWI seems to offer a beneficial non-invasive tool in evaluating passive venous congestion patterns in pediatric patients with VGAM. It remains to be determined in larger studies, the clinical significance of these SWI changes. 相似文献55.
Timo Jaakkola Harto Hakonen Anna Kankaanpää Laura Joensuu Janne Kulmala Jouni Kallio Anthony Watt Tuija H. Tammelin 《Journal of Science and Medicine in Sport》2019,22(1):85-90
Objectives
This study aimed to investigate cross-lagged associations of leaping skill and throwing–catching skills with objectively measured moderate-to-vigorous physical activity (MVPA) and sedentary time (ST) during school transition from upper primary (Grade 6) to lower secondary school (Grade 7).Design
This study is a one-year prospective follow-up study within Finnish school settings. Students’ MVPA, ST, leaping skill and throwing–catching skills were measured at Grade 6 and subsequently at Grade 7.Methods
A sample of 336 students (163 girls, 173 boys; M age = 12.0 years, SD = 0.4 at Grade 6 participated in the study. Students’ MVPA and ST were measured objectively by hip-worn accelerometers. Leaping skill was measured by 5-leaps test. Throwing and catching skills were measured by throwing–catching combination test. Cross-lagged structural equation modeling was conducted to evaluate the associations between MVPA, ST, leaping skill, and throwing–catching skills at Grade 6 and Grade 7.Results
Results demonstrated three significant cross-lagged associations among girls: (1) leaping skill measured at Grade 6 was negatively associated with ST at Grade 7; (2) objectively measured MVPA at Grade 6 associated positively with leaping skill at Grade 7; and (3) throwing–catching skills measured at Grade 6 associated positively with leaping skill measured at Grade 7. There were no statistically significant cross-lagged associations between the study variables for the sample of boys.Conclusions
The results of this study indicated that supporting opportunities for girls’ engagement in both MVPA and leaping skill development activities during their primary school education is strongly recommended. 相似文献56.
57.
Peyman Sardari Nia Jean H.T. Daemen Jos G. Maessen 《The Journal of thoracic and cardiovascular surgery》2019,157(4):1567-1574
Objectives
The aim of this study was to develop a high-fidelity minimally invasive mitral valve surgery (MIMVS) simulator.Methods
The process of industrial serial design was applied based on pre-set requirements, acquired by interviewing experienced mitral surgeons. A thoracic torso with endoscopic and robotic access and disposable silicone mitral valve apparatus with a feedback system was developed. The feedback system was based on 4 cameras around the silicone valve and an edge detection algorithm to calculate suture depth and width. Validity of simulator measurements was assessed by comparing simulator-generated values with measurements done manually on 3-dimensional reconstructed micro-computed tomography scan of the same sutures. Independent surgeons tested the simulator between 2014 and 2018, whereupon an evaluation was done through a questionnaire.Results
The feedback system was able to provide width and depth measurements, which were subsequently scored by comparison to pre-set target values. Depth did not significantly differ between simulator and micro-computed tomography scan measurements (P = .139). Width differed significantly (P = .001), whereupon a significant regression equation was found (P < .0001) to calibrate the simulator. After calibration, no significant difference was found (P = .865). In total, 99 surgeons tested the simulator and more than agreed with the statements that the simulator is a good method for training MIMVS, and that the mitral valve and suture placement looked and felt realistic.Conclusions
We successfully developed a high-fidelity MIMVS simulator for endoscopic and robotic approaches. The simulator provides a platform to train skills in an objective and reproducible manner. Future studies are needed to provide evidence for its application in training surgeons. 相似文献58.
Katherine M. Stenson Benjamin O. Patterson Matthew Joe Grima Jorg L. De Bruin Peter J.E. Holt Ian Loftus 《Journal of vascular surgery》2019,69(1):53-62.e1
Background
Endovascular aneurysm sealing (EVAS) represents a novel approach to the treatment of abdominal aortic aneurysms. It uses polymer technology to achieve an anatomic seal within the sac of the aneurysm. This cohort study reports the early clinical outcomes, technical refinements, and learning curve during the initial EVAS experience at a single institution.Methods
Results from 150 consecutive EVAS cases for intact, infrarenal abdominal aortic aneurysms are reported here. These cases were undertaken between March 2013 and July 2015. Preoperative, perioperative, and postoperative data were collected for each patient prospectively.Results
The median age of the cohort was 76.6 years (interquartile range, 70.2-80.9 years), and 87.3% were male. Median aneurysm diameter was 62.0 mm (IQR, 58.0-69.0 mm). Adverse neck morphology was seen in 69 (46.0%) patients, including aneurysm neck length <10 mm (17.3%), neck diameter >32 mm or <18 mm (8.7%), and neck angulation >60 degrees (15.3%). Median follow-up was 687 days (IQR, 463-897 days); 37 patients (24.7%) underwent reintervention. The rates of unresolved endoleak are 1.3% type IA, 0.7% type IB, and 2.7% type I. There were no type III endoleaks. There have been seven secondary ruptures in this cohort; all but one of these patients survived after reintervention. Only one rupture occurred in an aneurysm that had been treated within the manufacturer's instructions for use (IFU).Conclusions
The rate of unresolved endoleaks is satisfactorily low. The incidence of secondary rupture is of concern; however, when the IFU are adhered to, the rate is very low. The results of this study suggest that working within the IFU yields better clinical results. 相似文献59.
David C. Johnson Steven S. Raman Sohrab A. Mirak Lorna Kwan Amirhossein M. Bajgiran William Hsu Cleo K. Maehara Preeti Ahuja Izak Faiena Aydin Pooli Amirali Salmasi Anthony Sisk Ely R. Felker David S.K. Lu Robert E. Reiter 《European urology》2019,75(5):712-720
Background
Multiparametric magnetic resonance imaging (mpMRI) undoubtedly affects the diagnosis and treatment of localized prostate cancer (CaP). However, clinicians need a better understanding of its accuracy and limitations in detecting individual CaP foci to optimize management.Objective
To determine the per-lesion detection rate for CaP foci by mpMRI and identify predictors of tumor detection.Design, setting, and participants
We carried out a retrospective analysis of a prospectively managed database correlating lesion-specific results from mpMRI co-registered with whole-mount pathology (WMP) prostatectomy specimens from June 2010 to February 2018. Participants include 588 consecutive patients with biopsy-proven CaP undergoing 3-T mpMRI before radical prostatectomy at a single tertiary institution.Outcome measurements and statistical analysis
We measured mpMRI sensitivity in detecting individual CaP and clinically significant (any Gleason score ≥7) CaP foci and predictors of tumor detection using multivariate analysis.Results and limitations
The final analysis included 1213 pathologically confirmed tumor foci in 588 patients with primarily intermediate- (75%) or high-risk (12%) CaP. mpMRI detected 45% of all lesions (95% confidence interval [CI] 42–47%), including 65% of clinically significant lesions (95% CI 61–69%) and nearly 80% of high-grade tumors. Some 74% and 31% of missed solitary and multifocal tumors, respectively, were clinically significant. The majority of missed lesions were small (61.1% ≤1 cm); 28.3% were between 1 and 2 cm, and 10.4% were >2 cm. mpMRI missed at least one clinically significant focus in 34% of patients overall, and in 45% of men with multifocal lesions. On multivariate analysis, smaller, low-grade, multifocal, nonindex tumors with lower prostate-specific antigen density were more likely to be missed. Limitations include selection bias in a prostatectomy cohort, lack of specificity data, an imperfect co-registration process, and uncertain clinical significance for undetected lesions.Conclusions
mpMRI detects less than half of all and less than two-thirds of clinically significant CaP foci. The moderate per-lesion sensitivity and significant proportion of men with undetected tumor foci demonstrate the current limitations of mpMRI.Patient summary
Magnetic resonance imaging of the prostate before surgical removal for prostate cancer finds less than half of all individual prostate cancer tumors. Large, solitary, aggressive tumors are more likely to be visualized on imaging. 相似文献60.
Mae Lynn Reyes-Rodríguez Hunna J. Watson Concepción Barrio Donald H. Baucom Yormeri Silva Kiara L. Luna-Reyes 《Eating disorders》2019,27(2):205-229
ABSTRACTLatinos are less likely to seek health care for eating disorders and more likely to drop out of treatment than members of other ethnic groups, highlighting existing challenges to engagement in traditional mental health care. This study explored the role of family in the treatment of adult Latinas with eating disorders through content analysis of family sessions adjunctive to cognitive behavioral therapy. This study yielded insight into the experiences of 10 Latinas with eating disorders (M age = 39.90 years) and 10 relatives (M age = 39.50) from the Promoviendo una Alimentación Saludable trial who were randomly selected to receive six family enhancement sessions. Data from 53 sessions were analyzed using a qualitative content analysis approach. Family intervention might serve as a valuable adjunct to conventional treatment by positively influencing social, family, and emotional support for Latinas with eating disorders. 相似文献